7-OH-DPAT antagonizes dopamine D2 receptor-inhibited adenylyl cyclase activity

(+/-)7-OH-DPAT (7-hydroxy-2-(di-n-propylamino) tetralin) binds to both dopamine D2 and D3 receptor subtypes. In 7315c pituitary tumor cell membranes, which express only the D2 type of dopamine receptor, dopamine inhibited, and 7-OH-DPAT had no effect on adenylyl cyclase activity. When combined, 7-OH-DPAT antagonized the inhibition of adenylyl cyclase produced by dopamine. Thus, it appears that 7-OH-DPAT acts as an antagonist at dopamine D2 receptors.